The present invention relates in general to a mobile food serving system characterized by being energy saving, and pertains, more particularly, to a system for thermalizing the food, maintaining the food in a heated edible condition, and delivering the prepared meals to locations remote from the place of preparation. The system of this invention may have use in the feeding of patients in hospitals, nursing homes, airlines and other institutions. It may also be used in the feeding of hotel guests. Also, although the principles of this invention are preferably applied to a mobile system, they may also be applied to a stationary food serving system.
U.S. Pat. No. 3,924,100 discloses a mobile food serving system that is adapted for the delivery of prepared meals from a central location and with the maintenance of the proper temperature of these meals. This patent discusses in some detail the disadvantages associated with both a centralized system and a decentralized system. It appears that the centralized system may be more desirable from a standpoint of cost and efficiency. Even so, with this centralized system, there is still a requirement for a large heating apparatus such as steam pans or convection ovens in the central area. With these systems the food is, after rethermalization, placed on trays and delivered to the patients on different floors.
Many of the other systems now used especially in hospitals employ the centralized control with the use of microwave ovens for heating, preferably at each floor where food is to be served. At first appearance it would seem that the rapid heating available with the microwave system would provide some time and cost saving. However, a decentralized microwave system is extremely labor intensive requiring an excessive number of steps of handling the food. With such a system, once the food has been transported to the floor, each dinner must be removed and individually heated and then groups of dinners are served, usually in relatively small groups in order to maintain the food suitably heated. There is therefore a requirement for substantial help in the hospital for handling these steps that totally negates any advantage to the use of microwave energy.
It is an object of the present invention to take more full advantage of the centralized system by providing a food serving system that itself provides rethermalization and delivery of the meals. The rethermalization and the delivery system is preferably embodied in a single unit in the form of a self-powered cart.
Another object of the present invention is to provide an improved mobile food serving system that will enable simplification of the main preparation area by substantially reducing the need for large heating apparatus such as steam pans or convection ovens located in the main preparation area. Further, because of the use of this centralized delivery system there will be a significant cost saving in that substantially no extensive support equipment will be required on each floor.
Still another object of the present invention is to provide a food serving system having energy saving features. Because the mobile system is transported from place-to-place the system is provided with its own storage battery or group of batteries. However, in order to conserve the life of these batteries, the system of this invention makes optional use of a conventional power line such as the 110 VAC line. In that way the on board battery can be used primarily only for transportation purposes with most of the food heating being provided via an AC source. Furthermore, in accordance with the invention, food heater operation is controlled so as to maintain battery drain relatively constant. Thus, when a pulsed heating mode is employed, as defined hereinafter, it is preferred that not all tray heaters be on at the same time but rather that some heaters are on while others are off and vice versa. In this way battery drain is kept more constant and periodic surges are minimized.